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Volume 37, Issue 8
Displaying 1-9 of 9 articles from this issue
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Yasuji OHTSUKA, Yoshiaki HIRABAYASHI, Shigeki TAKAYAMA1980 Volume 37 Issue 8 Pages 507-514
Published: August 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSGraft latexes were prepared by graft-copolymerization of acrylonitrile (AN) -2-hydroxyethyl methacrylate (HEMA) mixture onto poly (vinyl alcohol) (PVA) in aqueous solution using eerie ammonium nitrate, and graft latex membranes were made by casting the latexes in air of 65% relative humidity at 20°C. The graft latex membranes that had well-balanced hydrophilic and hydrophobic components 24-28wt% of PVA, 56-64wt% of PAN, and 8-19wt% of poly (2-hydo-xyethyl methacrylate) (PHEMA) were excellent in solute permeabilities compared with a cellulosic membrane, Cuprophane PT-150. In addition, blood compatibility and antitoxicity were superior to those of silicone for medical use. But water permeability was inferior to that of Cuprophane PT-150.View full abstractDownload PDF (1216K) -
Takeshi AKAHANE, Takani MOCHIZUKI1980 Volume 37 Issue 8 Pages 515-520
Published: August 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSX-ray diagrams of a film obtained by rolling a sheet of high-density polyethylene at elevated temperatures showed that crystallites were doubly oriented and the (100) planes of the crystallites were parallel to the film surface. When the film was rolled again at room temperature to the direction perpendicular to the first rolling, the chain direction remained unaltered. However, at initial stage of the second rolling, the strongest diffraction of the quasi-stable crystal form (type II) was observed at the inner part of the 110 diffraction pattern. For the film rolled by higher ratio, (110) planes became almost parallel to the film surface and the diffraction of type II crystal was observed only in the direction of the film surface. It was concluded from these results that the formation of type II crystal is due to the slip on {110} planes whereby half number of planar-zigzag chains rotates so as to be parallel to the slipped planes. By annealing the film, the planar-oriented type II was transformed into the ordinary crystal form whose (110) planes were almost parallel to the film surface. The result may be explained by considering 90° rotation of half number of chains in the type II crystallites.View full abstractDownload PDF (1897K) -
Takeshi AKAHANE, Minoru UEDA, Shizuo TSUCHIYA, Haruo NAKAYASU1980 Volume 37 Issue 8 Pages 521-525
Published: August 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSVinyl alcohol polymers were heated in air and in the absence of oxygen to examine the cause of the discoloration of the polymers. While films of ethylene-vinyl alcohol copolymer (EVAL, hydrolysed copolymer of ethylene and vinyl acetate) were not discolored by heat treatment under vacuum or in the atmosphere of nitrogen, poly (vinyl alcohol) (PVA) fibers heated under the same conditions showed a clear blond color with a remarkable dichroism. Light absorption spectra of the colored PVA heated in the absence of oxygen showed absorption peaks corresponding to n=5-6 for the conjugated system- (CH=CH) n-CO-. The ethylene-vinyl alcohol copolymer heated in air showed yellow-brown color like PVA heated in air. It was concluded from these results that the color observed when PVA was heated in the absence of oxygen was mainly due to the conjugated double bond system. And the color observed both in PVA and in EVAL heated in air might be mainly due to condensates of aldehydes formed by thermooxydative decomposition of the polymers, and not due to the conjugated system.View full abstractDownload PDF (803K) -
Shinzo KOHJIYA, Masaru MATSUZAKI, Shinzo YAMASHITA1980 Volume 37 Issue 8 Pages 527-533
Published: August 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSCopolymers of cyclopentadiene (CPD) and butyl vinyl ether (BVE) have been synthesized by cationic copolymerization and vulcanized with a sulfur-accelerator system. Deterioration of the vulcanizates was investigated for standing in Geer oven at 90°C, in air at room temperature, and in outdoors. Polybutadiene becomes more resistant to oxidative degradation simply by sulfur vulcanization, but CPD-BVE copolymer remains to be susceptible to it even after the vulcanization. The vulcanizate of carbon black stock of the copolymer is also degradable. ATR infrared spectroscopy of the vulcanizate indicated the presence and augmentation of the peaks due to hydroperoxy group, hydroxyl group, and carbonyl group during the deterioration. Swelling- and mechanical-property measurements of the vulcanizate suggested that some cross-linking reactions are prevailing during the oxidation, which is in conformity with the results on unvulcanized CPD-BVE copolymer. Analyses by the Charlesby's procedure also confirmed the prevalence of the cross-linking over the chain-scisson reactions. Radical-acceptor-type antioxidants were found effective also for the vulcanizate. By solvent extraction of the vulcanizate, it became degradable again losing compounded materials.View full abstractDownload PDF (1126K) -
Kaoru FURUKAWA, Takashi AKIYAMA, Yoshio FUJII1980 Volume 37 Issue 8 Pages 535-541
Published: August 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSToyobo Co., Ltd., Research Center (1300-1, Honkatata-cho, Otsu, 520-02 Japan) Polymerization of caprolactam (CL) in a closed system in the presence of water and a phosphorous oxy-acid or its derivative was investigated. The most effective catalyst for the polymerization was phosphoric acid. By monitoring the amount of orthophosphoric acid in the course of the polymerization, it was confirmed that the derivatives of phosphorous oxyacids (phosphoric acid, phosphorous acid, and phosphinic acid) were easily converted to orthophosphoric acid by a hydrolysis and oxidation. However, organic phosphorous compounds containing P-C bond were not transformed to orthophosphoric acid during the polymerization. Kinetic study of the polymerization indicate that the phosphorous compounds work as the catalyst not because they promote the addition reaction of CL but because they do the ring-opening of CL. Correlation between the amount of phosphoric acid in the feed and the degree of polymerization of the produced polymer indicate that the phosphoric acid was bonded as a monofunctional viscosity stabilizer to the chain end by an ionic bond but not a covalent bond.View full abstractDownload PDF (1161K) -
Hiroharu HORIUCHI1980 Volume 37 Issue 8 Pages 543-547
Published: August 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSMixtures of aqueous poly (vinyl alcohol) (I) and poly (methacrylic acid) (II) were potentiometrically titrated with tertiary-amino compounds of low basicity. With these weak bases II gives titration curves similar to those obtained with alkalis or quaternary ammonium bases, irrespective of the presence of I Free energy changes for the globule-coil transition of II, ΔGc, estimated from the extrapolation of the titration curves, lie between 100 and 140 cal/mol. ΔGc, values are higher in the presence of I and have a maximum near the correspondence degree, α′ (I/II in mole) =0.1-0.2. Free-energy changes of I-II polycomplex formation, from the difference in ΔGc of II with and without added I, lead to the conclusion that for the conformational transition of II there is a more stable nonequimolar polycomplex or complex state in the α′ region 0.1-0.2 than at equimolar condition.View full abstractDownload PDF (899K) -
Naoki NEGISHI, Tooru SUZUKI, Minoru MOMIYAMA, Isao SHINOHARA1980 Volume 37 Issue 8 Pages 549-554
Published: August 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe effect of polymer matrix on photocuring was investigated in connection with the molecular motion of polymer-chain segments in poly (alkyl methacrylate) -aromatic bisazide systems. On UV irradiation to the film of poly (n-butyl methacrylate) (PnBMA) system, the polymer became insoluble in tetrahydrofuran by the photodecomposition of azide groups. The gel fraction of PnBMA matrix which showed low glass transition temperature (Tg) was higher than that of poly (isobutyl methacrylate) (PiBMA) matrix which had high reactive side-chains for nitrenes at 30°C. On raising the irradiation temperature, the gel formation was observed in order of PnBMA, PiBMA, poly (ethyl methacrylate), poly (isopropyl methacrylate), poly (methyl methacrylate), and poly (t-butyl methacrylate) systems, and this order was in line with that of Tg of the polymer matrices. From these results, it was concluded that the molecular motion of chain segments of matrix polymer played an important role in the photosensitivity of the polymer-aromatic azide systems.View full abstractDownload PDF (935K) -
Takeshi AKAHANE1980 Volume 37 Issue 8 Pages 555-561
Published: August 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSX-ray line broadening of doubly-oriented poly (vinyl alcohol) films, obtained by rolling and annealing, was measured to investigate the effects of crystal size and lattice distortion. The 200 line profile assumed a shape intermediate of Cauchy and Gaussian in the vicinity of the peak, and was approximated by a Cauchy distribution at the tails. Integral line breadths of 100, 200, and 400 showed that the lattice distortion was rather of microstrain type than of paracrystalline type. In evaluating the effects of crystal size and lattice distortion, especially in the case where only two different orders of diffraction were observed, it was concluded that more satisfactory results were obtained with the assumption that the broadening due to the crystal size was Cauchy, while the broadening due to the lattice distortion was Gaussian, than with the assumptions that both broadenings due to the size and the distortion were Cauchy or Gaussian. This conclusion was consistent with the shape of X-ray line profiles.View full abstractDownload PDF (1219K) -
Shogo NIINO, Kentaro AGEISHI, Shigeru HAYAMA1980 Volume 37 Issue 8 Pages 563-566
Published: August 25, 1980
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSBiphenyl-4, 4′-bisazothioaryl ethers in solution decomposed at about 70°C to give mixtures of diaryl disulfides and oligo (4, 4′-biphenylene) s, via the formation of biphenylylene radicals and thiyl radicals. These bisazothio ethers worked simultaneously as initiators and comonomers towards various viny monomers to give copolymers containing biphenyl units in the chains. The copolymers as well as oligo (4, 4′-biphenylene) s contained approximately two terminal arylmercapto groups per chain. Kinetics of the polymerization indicate that terminal arylmercapto groups in these polymers might be formed not by recombination of the primary thiyl radicals, but by a chain-transfer reaction of active ends of growing chains to diaryl disulfides. o-Substituents on the thiophenyl groups restricted the chain-transfer reaction.View full abstractDownload PDF (649K)
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